Testing system



15 1927' w. 1.. LAwsdN ET TESTING SYSTEM! Filed Jan. 1926 2 Sheds-Sheet 1 i W/f 1 3/7 mm 0W 0 #rvemars. MW g me/d 1,617336 Feb. 15, -.w. L LAWSON ET AL I 9 I TESTING SYSTEM Filed Jan. 16. 1926 2 Sheets-Sheet 2 5 the associated line andcut oil relays;

= another.

i I fplet'ed to s indicate [that the corresponding particular jack ;eir"cu'it j der test Anabel feature is the provision Fo'f means f fwhereby the reuersal or -any other 'unsta-nd I ns of-the conductors ina ny 'jacki Patented Feb. 15 192.7, d

wI LLIAi/I'L. LAWsoi or'oliK PA RK iLLmo s; "aiin mynoixi GANFIELD, oF F UsH time ING, new YoaK, ASSIGNORS T WESTERN ELECTRIC COMPANY, INCORPORATED, or

NIEW YORK N. Y A coRPoRAmonor new 7103K. I

IITESTIIIIING SYSTEM;

Apphcation filed January 16, was. :Serial lie 81,666.

This inventionrelates: to -testing systems and more particularly to fan'improved arrangement for testing operating characteristics of ordinary answering jack circuits and An object of the invention is to combine in a single inexpensive test set a greatlysi nplified' circuit arrangement for performmg operating tests of a plurality of answeri ing jackcircuits and the c'orresponding: line and cut-oil relays-and for observing and analyzing var1ous "unstanda-rd conditions that may arise in these apparatus without shifting the test setfroin one jack circuit to A :ie'ature ofthis: invention is the provisum of meanswhereby continuity testsof I the tip,'ring and sleeve conductors ofa plufrali'ty of answering ackcircuits totheir respeetive line and cut-oft relays may he automatically performed in succession;-

1 ki notherefeature of the invention th provision of means Wherehya signal is given "after theeontinuity 'test of the individual conductors of each answering] jack is COIZQ- 'cir uitis in a standard condition.

' Another feature of the invention is'the provision of a manually operated key to i start the r"unetioningjof the automatic conr 'tinuity tests, andafterthe test set has been ass'ociated with a plurality of answering'jack circuits.

Another ieaturefoftlie "inyen tion is "the checked during; I corresponding ack clrcuits.

the" continuity tests of the 5 jinother feature of the 'nve'ntion "is the II I I I 4 progress and" outcome ofuthe d fi'erent tests gperfornied by the set as willfhere nafteigbe ideserib'ed. 'To; automatically"advance the" testing from onefanswer'ing jack circuit/$0 I 'another-there is zprovideda series of autoinaticallyoperating rotary SWitchesBEg to 540 which may ibe actuated by 1 the steppmg I I 3 magnethetla to aadvancezwthej brush [contact III-0' proiisienio'f' nieans whereby i'n a system for testing the cont-minty I of a plurality" of ack circuits andthe associated relays" the consucceeding circuits is prevented Another feature s the provision-of ineans whereby signals are provided to i d serted-i I I I L;may-loe:arranged in'a singlecord-I12 and ma) te'rinihate!at the oppositeend in corre s endin plugs 13, tel? arrangedin a single holder 18. Tlheplu'gs1-3 to l? are" therefore similarly adapted; toj be inserted simultacatethe I I e I nection withone Set*QihtGIHllIlRlSftftCl'fiIiother; AIoj start the test. set: operations and .circuit inay be detected and wherehyunder these circumstances the advance ofthe'test.

ofsucceeding circuitsis prevented.- I I II I Another feature .is the pro'vis on of means Y whereby ina" system for I testing the con;

tn'iuity' of aplurality of jack circuits the continuity tests of any vp artlcula-r jack 0ir-' cuit may 'bemad'ej to the exclusion'oif others. A "This-invention will; be described with I the aid of the accompanying drawings in which 7 1 illustratesa circuit-for a; test set arranged in accordance with this invention and Fig. 2-i'llustratesa plurality ,ofanswer I ing'i'jacks to be testedQand a ndulti-contact cord foryconnectingthetestjsetfwithsaid I answering jack's.-, I V I;- Y RGfGII'lIlgiJlOW to" the 'draw ng's'a test set. is llustrated thereinarranged; for the testing .otfiveanswering jack circuits at one I time; witliout shifting the manual connections between the set andzthe five answer ng aeks. 'To, this end the setisproyided with five jacks 'fl toi 5 into which the individual v plugs 6 to 10 arranged a single holder 11 may; be. respectively and simultan'eously in- The conductorsjof theseyplugs 6 to neously intoiive; answering jacks to be "tested such asjacks li) t0 '28.; llhe'eircuit for jackvl9 and its .associatedjlineand cut 7 loft relays ha've'lo'een shownin detail, Assn I ciated with jacks 1 to 5, are 'signal lamps :24 to 28 whiclnare arranged with "a plu- ,rality of other I signal lam'psf suchgasp 30' to so Y 34 in the'letest set-to variously-indicate the) thereof 0ne5stepat the time to; establish conto "m anipulatefit to performa'number of ,dif

,keys are provided. These keys are numbered 42*to. 56." Other "circuit connections during the testing operations areperformed by a plurality ofrelays, such as 57 to 69.

A resistance 76 and three adjustable resistancesv 71. to 73 and av milliammeter 74 are other apparatus provided in this set for 7 tests that maybe performed thereby.

checking the electrical characteristics of the circuits to be tested as will hereinafter be described.

To bring out the various features of the invention as embodied in this test set, a descriptioii will now be made of the various These tests may" be described as operating and adjustment tests of the cut-off and line relays of "five answering jack circuits and may be divided'iiito three groups. The first is the operation'or continuity tests of the answering-j ja'ck conductors and the second is'the adjustment-tests of the cut-olf relays while the thii'd-is the adjustment tests ofthe line relays, the last two tests relating to the checking and measuring the-"operating Tcharacteristicsof'cut-off and line relays.

To enable the test set to perform these tests,jacks l to 5 are connected through to jacks 19 to 23, respectively, by means. of the cordj12,a-Iid=to start the continuity tests keyv 52 iso'pei'atedf The operation of this key closes-a circuitfor relay 5? as follovvs:'bat-.

tery,'windiiig of stepping magnet41-,armature and back contact of this stepping 'magnet, normal inake-before-break contacts of relays 67 and 66, left-handv armature and back contact of relay 58, Winding of relay 57, contacts of key52 to ground. Relay 57 operates inthis circuit and closes circuits through from the line relay 100 associated (with jack 19 asfollows: one circuit from ground, left-hand Winding of line relay'100,

' inner riglit'armat'ure and backcontact of cutolf. relay 1'01, tip terminals of-jack 19, plug 13, plug 6, ack'. 1, to the corresponding terminal and the brush of switch 85, a closed pair .of

contacts of keys 46,45 and 43, outer righthandarinature and front 'contact'ofrelay 57,

v windings of relays 59 and. 60 in series to batteries-i right-hand winding of line relay 100,ring "Contact of jack 19 plug 13, plug 6 jack 1,

Another circuit from battery,

corresponding terminal and thebrush of a switch 86, 'a: closed pair of contacts of keys 46, 44-ai1d'43, inner right-hand armature and front-contact of relay 57, winding of relay 61 to' ground. If'the line relay1-00 is in a standardconditioini'elay 59 operates-iii the fii'st tra ed circuit but relay- 60 does not operate as it is inarginal and' does notre-" I spoi'id if the characteristics offthis-circuit are 1 normal. The operatioiiof relay' 59 clo'sesan obvious "circuit for lighting. oi signal lamp 30, which thus indi'cates that circuitv of [standard i character is closed through the line relay 106 and; the tip conductor of the circuits for answering jack 19. The opera:. tron of relay-59 also :closesan obv ous circuit'through the upper winding of relay 63 causing the operation of this relay. -The operation of relay59 also closes partly a circuit forv the upper winding of relay" 64 in that a ground is appliedfrom'th'e armat'ureand" front contact of relay 59' through a closed pair of contacts of relay 46, to the lower armature and front contact of relay 61. The second mentioned circuit through the line relay 100 causes the operation of relay 61. Relay61in operating.- closes an obvious circuit for lighting of signal la1npY31, which thus=indicates that a circuit of stand ard character is -closed through the; other winding of line relay 100 and the ringconductor of the circuit for answering, jack 19. Anobvious circuit is also closed by-the operation 'of relay 61 through the lower: Winding tact to ground at the 'left-hand armature and front contact of relay 57 This relay 64 also closes partially a circuit for relay 66 at'its upper inner armature and front contact, the purpose of which will be he-reinafter described. Relay 64 also at its upper outer armature and front contact-closes a circuit for the operation of the cut off relay 101 of the circuit offjack '19. and for the operation of relay 62 over a circuit as fol-1 lows: battery, through adjustable resistance a pair of closedcontacts or key 49,'resist ance 70, upperouter armature and front contact'of relay 64, closed contact of key 53, wiiidingiof i'elay62, a closed pairof contacts ofkeys'44' and 45, the brush and the correspondingterminal of switch 37, sleeve conductor of jack 1, sleeve terminals of jack 1, plug 6, plug; 13, jack 1 9,.-wiiiding' of. cutoff relay 101 to ground. This circuit causes the operation of i elays62 and 101. The :op-

.eration of relay 62 closes an obvious circuit for the lighti ng of signal lamp which indicates that a circuit of standard char .acter is closed through the cut-off relay 101 and the conductor-of the circuits for answering jack 19 It should be noted that a. tester mm observe the. li htin other) 162 assocu m l ciated with the circuits of jack 19.611 the operation'of the line relay Qandthe ex -tinguishing of this-lamp on the operation' of'cutoff'relay' 191.1 The continuity tests of the circuits foranswering jack 19 are now i completedand the continuity; tests of the circuits for the next answering jack in the case, namely jack 20, may be made.

1 I'tishould be noted that'on the operation of the cut off relay 161, the circuits for the operation of the line relay 100 and the -relays" 59 and 61 are open'at the right hand armatures and back contacts of thecut-ofi' relay 101. This causes the releasei-of line relay 100 and relays 59 and 61Iand the release-of these last two relays causes the release-of T v relay 63. The release of relay 63 now closes a circuit for the advancement of the selector brushes to the tip, ring and'sleeve terminals for the tip, ring and sleeve conductors of the second circnit,; that; is, the circuit for performing the "continuity tests of the cir cuits for jack 20. The circuits for this ad- Vance of the selectors inay be traced asfo lows; the first circuit isclos-ed duetof the releaseof relay63 and is asfollows: battery lower inding of relay66, a pair of closed contacts of key 49, lower armature fallfClbtlCk contact of relay 65,- upper 1nner' armature.

and front'contact'of relay 64, armature and back contact of relay 6-3 to ground. This circuit causes the operation of relay 66. operation of relay '66 opens the energizing circuit for relay 57st its make-before break contacts. On therelease of relay 57 ,.relay' 64 islreleased which opens the originaleri:

ergizing circuit for-relay '66. Relay GtS is,

however, maintained operated through its upper Wind ng, upper armature and front Contact, makebefore-breakcontact of relay :67, armature and back contact ofgstepping magnet hbrush of switch lower arnia- V ture and front contact of rela' 66 a pair of "closed contacts 'of key to ground; The

operation of relay 66 thus provides through the'closingofits lower armature and front ,contact, a circuitfor the operation ofistep ping magnet 4i asfollows; battery, ind

ing of stepping magnet 41, the first termi nal: and I brush of vswitch 40, lower arrnature and front contact of relay 66, a pair of closedcontacts of key 50 togrounjdi The stepping magnet le operates in this circuit and moves the brushes of the switches. 35 to 40' one step. As the brush of switch 40 moves from the first terminalf'the selector magnet 41 and relay 66 are released. WVhen this magnet and relay are released theorig inal energizing circuit for relay 57 is again closed through the inake-before-break contact of relayv 66"and through the armature and back contact" of stepping magnet 40 4s hereinbefore described, The continuity tests; i of the circuits-for "jack QOj may now there "fore,b egin through th-e operation of relay 5'? v and the tip. andring connections for the line- Yrelay associated with vjack '20 are closed to operate relays 59 and 66 and theoperation of the linerelay associated-With jack, 20; fola lowedby the operation oft-relays 66 brushesv thesyyicches and the operation ofthe cut-off relay ofthe circuits relay 62.

The operation of the cut relaycauses; as before stated, the releaseofzrelay 6'3 fol lowed by the operation of relay .66 and the forjack ZOIand the operation of I '7 advance of the selectorsiyitcheslfifi-to to circuits for succeeding answering'fjacks zl, 22 and 23 areprovided for andperformed in success1on.-;-As these tests are performed -itWilLbeqnotedthat lariipsQjto 28. are lighted in succession 'to indicate the, pan

ticularanswering .jack under. test ata'ny tiniefl This lS EICCOIDPllShQ Ql through the brush and corresponding terminals of switch 38, that: isffor example; 'When' jack 19 *is test-ed, a circuit will beflcoinpleted for lanip 24; to .battery,: lainp; 24: through the first terminaland the brush :of switch 38gto the conductors ofthe circuits for. jack 21 Ingthis' nannenthe'ic'ontinuity testof the l ground, and correspondinglycircuits will be closed in; succession lamps jacks 20 was are tested,

If it is desired"to makerthe. above c011 tinuity tests conly the key 55 should be op eratedsiniultaneously'with the operation of I key 52 at the. beginningj'of the vtests. If this,

25 to 28 as is the case, the buzzer78; ill:operate at the;v

completion, of the continuitytests for. the

'circuits of the tes'tEjack in the group name- I jly jack 23, in the 'followingimannerz When the {switch has finished the testing of the circuits, of jack 23,' the [brushesf'of the switches 35to 40 Will be'located'on the [fifth terminal. "In this position a circuit 'Wlll now be closed rforvbuzzer 78 asfollowsa battery, i

Winding of buzzer 'l' c left-hand" closed con tacts of; key '.5 5,cthe fifth terminal of switch 40 and its corresponding brush; lower armae v tune and front 5 contact. of relay 66, a pair iof; clos-edcontactsof key i50.t'o groun'd'. 1 c

The operatorhearing the soundnm the buz'ZerE itilll then i remove the plugs 13 to 17 i from g acks 19 to 1 23" and insert these iplugs ln another "set of five answering acks Whereupon the continuity test ofthefcircuits forthese jacksniay proceed. To open the circuit I for- ;the buzzer jand adya-ncex thef'selector switches first' to, the sixth; terininal position; and'later through the seventh to, the eleventh terminal position'in readiness to V tl'ieftest jagthis: second set of answei-ii'i'g jacks, ,7 key-.51 Wlll DOlV be. operated. The opera-Q t-ion'ofthis' key close s 'an obvious chergiz:

ing" circuit forv relay 67. which in. operating closesat itsf low er, armature and @front; con- Pi e eg-He ne d opens the bu'zzer circuit"and on the opera-I" position. If'the key 51 is now operated five times in succession the relay 67 and consequently, magnet 41 will operate the corr'e sponding number of times to advance the se- -lector switches until. their brushes come to.

rest in their eleventh terminal position. It will be noted that in this position lamp 2 1 7 will becomelighted so that the tester will now know that the continuity test of another set of fiveanswering jacks may begin. By virtue of theplugs 13 to 17 of the cord 12 being inserted in said second group of answering jacks and the switches being'ad vanced to the eleventh terminal position, the testing of the circuit for the first of these jacks will begin'as' relay 57 was reoperated onthe release of relay'67 and the release of magnet 4:1.and the circuits from the tip and ring conductors of this first 'jackwill' be completed through to the relays 59 to 61 as hereinbefore described. In this manner, two successive sets of five jacks each may be tested for continuity by shifting the plugs 13 to 17 each time the buzzer 7 8 is heard from one set of five answering, acks to another and thek-ey 51 has been operated the required number of times between each test of five answering jacks each to advance the se so.

lector switches 35' to 40. past terminals 6 to '10 and 16 to 20. These terminals 6: to

are

"tothe 20th terminal positions as will' be the case after two sets of answering jacks have been tested for continuity of jack circuits or when both continuity and adjustment tests have been made as will be hereinafter del "scribed,-the operation of key 5lwill advance the selector brushes to the 21st 'position in r a manner as hereinbeforedescribed and whentthis' position is reached the selectors 1 are automatically returned to the normal 'po-- sition shown in the drawing. This is acconiplished asqfollows: In the 21st position a circuit is closed for the operation of relay 57 so that thetip. andring conductors of the "test set are connected up from thebrushes of switches and 36 to the relays '59 and nd61. Ground on the brush of 'switch65 from terminal 21 causes the operation of re lays 59 and 60 andthe operation of relay '60 closes an obvious circuit for relay Relay'65 lin operating provides a locking circuit for itself to ground at the left-hand armature and front contact. of relay 5?. This relay 65 also closes a circuit for the operation' of relay 66 as follows battery; lower :winding of relay 66-, a pair of closed contacts of key49f, lower armature andfront contact of relay 65,6terminal 21 of the brush leading to this cut-off relay.

switch 39 to ground. Relay 66 in operating causes the advance of the selectorswit-ches 35 to- 40 to the 22nd positi'on'by closing the circuit for magnet 11 to its lower armature and front contact and terminal 21 ofswitch 41 as the switchesmove from position 21 to position 22 all of these relays are released and when the 22nd position is reached the above operations are repeated and the switches thereby returned to normal position. i

It will he noted that during these continuity tests described above,-the so-called adjustment tests of the cut-off relays are automatically performed, that is the circuits for the cut-off relays comp'leted through relay 62 are also extended through the adjustable re sistance 22 which may be set to provide the proper electrical characteristics of the test circuit. If any particular cut-ofi relay does not'operate during these tests to extinguish the line lamp of the associated answering jack circuit such failure may be dueto the faulty fldjUStHlenhOfillG cut o-fi relay or to some unstandard' condition in the circuit therefor in the particular answering jack circuit under test. To ascertain the source of'such failure in the operation of the cutoff relay key 53 may be operated; By operating this key, a so-called soakvalue of current may be placed through the cut-off relay winding by the opening of thecircuit.

for this relaythrough theadjustable resistance 22 and the resistance 7 O and the clos ing of a connection. directly from a winding of the relay 62 to battery at the nowclosed contacts of key 58. If this particular cut-off relay now operates it would indicatethat the electrical characteristics of the winding of this particular cut-off relay were at fault.

Ifrelay 62 vdoes not operate some unstandard 7 condition exists in the sleeve conductor If it is desired to perform adjustment tests of the line relays o'f a particular group of five answering jacks connected for "test immediately after the'continuity tests of the circuits therefor and the adjustment tests of thecutoff rela-yshave been performed the key 55 is not o'perated'wit'h key 52 at the beginningof thev tests but allowed to remain in a normal position. it willbe noted that at the completion of the tests of the five answering jacks and while the brushes of the switches 35" to -10 are in their; fifth posi tion, a circuit will be closed to prepare the set' for ad uStment testsof the line relays.

A circuit for'starting these operations will of key 55,fiftl1 terminal and brush'of switch 40, lower armature and front contactof relay 66, a closed of contacts-of key 50 to ground." The stepping magnet will now take one additional; step and ,cause the brushes of switchesl to 4:0 to contact with their sixth terminals; At the operation of stepping magnet 41, the holding circuit; for

relay 66 will be open at the armature and back contact of this magnet thus allowing relay 66 to release and the original energizing circuit forrelay 57 is again closedat the normal contacts of therelay 66. In this position, the circuit for the -two 'windings of the line relay-IOO-Will be completed to the relays 59 and 60 and'61but it will be noted,

that these circuits" will v beimmediatelyopened and; other; circuits completed due to the operation of relay-58 under these cin 'cumstances which takes place over ,a circuit as; follows battery, Winding ofrelay 58,-av

pair of closed contacts of key 5 0,- a: pair of closed contacts of key '55, the sixth terminal of switch 39 and'thecorresponding brush to ground. The 'operation of relay 58opens the energizing circuit for relay57 which in releasing opens the tip and ring Iconductors from the line relay 100 to the relays 59 and 60 and 61 and relay-58 closes a-loop circuitfrom the ,windings'ofline relay 100 through thevads. justable resistances 71' and 72 as follows 2" battery, right-hand winding of line relay- 100, outerright hand armature and back pleted until relay 69 is operated which takes, place immediately upon theoperationof re-. lay 58. The-circuit for the operation of recontact ofcut-ofi' relay- 101, tipterminals vof jack 19, plug 13, plug6, jack l,'='sixthtermi- 11211 of switch 35 and the corresponding" brush, a pa-ir'of closed contacts of. key.46,

outer right-hand armature and front contact of relay 58, adjustable resistance 71, right.

hand armature and front contact of-relay 69, adjustable resistance 71, aipa-ir of closed contacts of keys 47 and 48, inner right-hand 58 a. pair of closed contacts of key l6, the blllSlL of switch 36 and its sixth terminalitolthetip and ring terminals of jack 1, plug 6, plug! armature an d front contact of relay 13, jack 19, "right-hand .i'nner armature and backcontact of relay 101,;left-hand winding of relay H to ground. vHowever, it:

should be noted that thiscircuitis not comlay 69 is asfollows: battery, winding of relay [69, a closedpair of contactsvof key 48,

, left-hand armature and back contact of'relay 68,-middle right hand armature and front contact of relay 58 to ground. The

resistances -71 and'72 are iadjusted to cause the proper electrical condition to prevail on the tip and ring conductors forthe opera tion of line relay 100 and to determinewhether or not line relay 100 is functioning properly, these circuits through the resist-t anc'e's 71 and -72 will be alternately opened and closed to causethe alternate lightingand extinguishing oflamp l0 2iin the. circuits'for jack 19a1'1d1of lamp-.34 thevtestpsetgThe circuits iforqthis purpose are-.asr'follows'; It;

willbe notedthat on the operation of relay 69' tlllgObVlOllS'ClIClllt is closed forthe operation ofrelay68 which in operating opens the;

energizing circuit for relay 69 so that When this relay releases, the relay 68-releases and-v again closes the circuit'for'the operation of;

relay 69. As. these relays 68 and 69 are slow to release, acircuitfor line ,relaylOO will be,

alternately, opened and closed at a definite rate: and consequently lamp, lO2ancllamp j are alternately lighted and-"extinguished to;

indicate -t-he;..operation and J release of the to.

line relay." By theproper adjustments of the resistances-7l and 72 therefore, the operating and release values oftheQ-Iine relay10O will be tested. YBy arranging the adjustment tests'of the line--relaysso that-the line lamps are alt rnately l ght ll an ex gu he a distinction isma'de between. thesetestsand the continuity tests.

: Itj'shoull be 7 notedjthat clue that the relay 66 is' notoperated in this circuit, the selector switches to t0 willj not ad ance f t e e iu m ntt Ofi he succeeding jacks in the group of jacks con,- nected; to the test; set but that the selector may be' advanced; for the testingjof thesesucceeding jackcircuitsby the manualpperationpf key;51.' The operation ofthiskey closedi an obvious circuit for the operation;

of relay 67,; The operation. of this relay;

closed anobviousjcircuit for the magnet ll to advance,thejselectors to connect the set in this-case jack 20. .When now, therefore,

-1OO with the circuits-of the next answering j ack,-

the brushes of these switches are advanced tojthe seventh terminal, the vcircuit forrelay 58 will beagain closed as previously traced except; thattheiground will now be supplied through from the brush of switch .39 at its seventh terminal, f l'n a similar manner the l nerelaysof the succeed ng answeringjacks,

7 8, right-hand armature andv front contact ofrelay 68, tenth'terminal ofswitch38 and its corresponding brush to gro'iincl'to, indi cate that the adjustment test of the line relay of the five answering jack circuits has been completed; I j i 7 If it is desired'to test the actual, operating value of ;a line relay, that is, in case a line relay'do es not operate on the proper adjust mentofresistances '71 and 7 2,the polnters,

7 5m'ay be moved-toward the right until a connected, linerrelay'does operate. To permit thistobe: done, a key 47 will ,be operated;

When this key isjoperateda circuit is closed:

for the operation ofrelay '58 asfollowsz battery, winding of relay 58, outer righthand closed contact of key 47 to ground.

The operation ofrelay 58 closes the test circuit from a line relay through the resistances 71 and 72- as hereinbefore described anda circuit is also thereforeclosed. for theoperation ofrelay 69- as follows: battery, wind ing ofrelay 69 a pair of closedicontactsof key 48, outer left-hand pair of closed con-- tacts of key 47'toground. The circuit for the milliamn'ieter 74 as follows; trom' rethe line relay to. be thus tested is. also closed through the 1 operation of key *47 to 74" that is, the actual operating value ot'any- "Similarly,- if it"isdesired to test the actual release value of line relay under test may be measured 1n, this manner i any particular 'linerelay, the key 48 maybe operated. In this case relay 58 will be operated-through an'obvious circuit-throughthe closedouter righthand contacts of key 48 and relay 69will be prevented from operating through the opening'offthe outer left-hand contact of key '4S'so that the loop circuit will be open; through slider 75 but closed through the slider 76 which may now be moved to the left until the. particular linerelay under test releases. Itshou'ldalso be noted that the operation otkey 48 closes this loop cir cuit for the line relay through the milliam meter 7 4 to measure the actual value of thecurrent at the time the line relay releases The circuit of this loop to the milliammeter 74' may be traced as follows: resistance. 72-, a'pairof closed contacts of key, 47 inner left-hand closedcontactsof key 48, apair of closed contactsof key 56,. th rough the' milli-am1neter-74', a pair of closed-contacts of key49, a pair of closed contacts of key 56, inner right-handclosedcontacts of key 48 to the inner right armature-and front contact of relay 58.-

If it is desired to measure the actual operating 'value of any particularcut-oft relay, key 49 may be operated. In this case, the circuit from the 'cut-off-relay' will not'go through resistance but may be traced from the battery, through the adjustable.

resistance 73, right-hand inner closed-contactsot key 49, a pairof closed contacts of key 56 through the milliammeter 74, apair of closedicontacts of key 56, inner left-hand closed, contacts oi"; key 49, the closed contacts of key. 53;, winding of relay 62 and out throughthe winding otthe particular cut-oft relay under test as hereinbet'ore traced to ground. The slider 761may now be movedacross the resistance 73- until the cut 05. relay connected .inthis circuit ope, crates and .,the operatingvalue of the. cur.- rent flowing in the circuit may be noted on the milliamineter 7 4.

The purpose otthe-key 56 in the circuits. above mentioned to. the, milliammeter 74 is tor. the purposeot reversing the current flow throughthejmeter in. case-the connections from the battery atjthejackcircuits; are poled in I the opposite direction it'ron' the usual f connections; af, condition thatf the tester. will be aware. of when conducting tests in difierent typesotswitchboardas. is

well-known,inthe art. a

If, during the continuity tests of a group of. answering jack circuits, it is tound that a particular jack. ClIQLllllydOGS not function properly, the tests of. any one oii-thesefcin cuits maybe. repeated by operatingkey 50 at the timethe unstandard co idition is observed; The operationofkey 50. closes an circuit. for the advance .of the: selector switches normally completed through the obvious circuit for the operation; ot},rel ayf lower armature and;fr01it.,contact.. of relay 66 andthat .is..in.this case opened at the outer. left-hand contacts of key 50. hen; therefore relay 661, operates on. the release of relay63, the. selector switches are not, advanced... Relay. 57, however, is released as under normal conditions on the operation. of relay. 66 causing the release o'f-relay- 6.4. which inturn causes the release o -[relay 66 a to again complete the. circuit for relayfoi In thismanner they test. for. the particular jack circuit dition has been observed is'repeated time and again until-key 50 is releasedat. which time the testsot the succeeding, jack circuits m'ayproceed, in the usualmanneia,

The 'unsta-ndard conditions above referred to that may occur during the continuity testing of jack circuits. andfadjustingtests of.

such as to preventits operation on currents through the tip. conductor. circuits below a certain ffpredetermined value... This. Value .may be the maximum allowable :fortip con- MU Jed lie on whichzan unstandardconductor circuits through line relays and'i-n of the reversing :keys as described above,

thismann'er whenever 'rclay .60, does operate it will be known that the current through the particular tip. conductor through the line relay under testis excessive. If relay operates, an obvious circuitis closedfor the operation of relay which in turn closes an obvious circuit for the lighting of lamp 63 to indicate this unstandard condition. Re-L lay 65 locks-to relay 57. It should be noted thatunder these circumstances the switches will not advance at the completion of the test of this particular jack circuit as relay 65 in operating will prevent the operation of relay 66 on the release of relay 63,

Qther unstandard, conditions may be that relays 59 and 61 tail to operate altogether or fail to release when the cut-off relay of the jack circuitunder test operates. In these cases the circuit for the operation of relay- 66 will not be completed sothat the selector switches will not advance and the signal lamps 30, 31, and 32 will then indicate the exact condition or cause of failure of the ackc1rcu1t under test. F or example, 1f

It lamp 3O fails to light and lamp 731 light-ed, this will indicate that the tip conductor is open. To ascertain if the tip and ring conductors are reversed key 43 maybe operated and if lamps 30 and 31 then light,

it indicates a reversal ot'these conductors. It

lamps 30 and 31 are lighted andlamp 32 fails to light, this will indicate that the sleeve conductor is open. If the lamp 32 and lamps 30 or 31 are lighted, this will indicate that the cut otl relay has failed to open the tip or ring conductors. If the'key 53 is then operated and lamp 32 and lamps 30 or are lighted, this will indicate that there is a ground on the sleeve conductor or thatthere is a'false ground or battery on the tip conductor or the ring conductor.

lamp 32 and lamp 33 are lighted, this will indicate that there is a ground between the f ground between the answering 'jack itself and the cut-off reiay on the tip conductor] If it is thought thatthe ring and'sleeveconductors are reversed key 44 may be operated,

and if the test then proceeds in the regular manner, it indicates that the analysis was correct. Similarly if itis thought that the tiprand sleeve conductors are reversed the I key45 may be operated audit the test then proceeds in the regular manner, it indicates that the analysis in this respect was correct. It will thus be seen that by these various combinations of signals and by the manipulation It the test, which will be indicated by the lighting of a particular one of the lamps 245 to- 28, corresponding to the jack circuit to be tested,

It then the start key 52jis operated-,the testing of thiscircuit may begin and it the key '50 is al'so operated, the testing of this circuit may be repeated.

What is claimed is I 1 1. In a system for testing telephone cir-' cuits, means comprising a plurality of plugending cords for temporarily and simuL taneously connectinga testing device to a plurality of. telephone circuits, and'means the exact condition of a particular answer cing jack circuitfunder test maybe indicated.

lt' it is desired totest any one of'the answering j ackfcircuits to the exclusion of all 'i others, key 51 may be operated a number of times until thefselector switches have been ,a d vanced to the jack circuit it is desired to M for automatically and successively testing such circuits. I

2. In a system for testing telephone circuits, means comprising a plurality of plug:-

ending cards with the plugs at each end assembled in a common handle for temporarily and simultaneouslyconnecting a testing device to a plurality of telephone circuits, and "means for automatically and successively testing the circuits;

3. In a system for, testing telephone circuits, means for temporarily andsimultane- 'ously connecting a testing device to a plurality of telephone circuits, means for automatically and successively testing such ciriim' cuits, and means for indicating in response to the performance of the tests onieach cir wit that the corresponding circuit is in" standard condition. y

4. In a system for testing telephone circuits, means for temporarily and simultaneously connecting a testing device to a plurality of telephone circuits, means for automatically and successivelytesting such circuits, means for discontinuing the automatic testing of any circuit after-the completion of'the tests upon any particular circuit, and

meansfor repeating'the tests upon this'particular circuit.

'5. In a'system for testing telephone circuits, means for temporarily and simultaneouslyconnecting' a testingdevice to a plurality of telephone circuits, means for automatically and successively testing such circuits, and means'tor actuating said testing device to perform the automatic tests on] any one of said clrcuits and eliminating the testing. of all the other circuits; T

6. In asystem fortesting telephone circuits, means for temporarily and simultaneously connecting a testing device to a plurality of telephone circuits, means for automatically and successively testing such circu ts, and signaling devices and keys for I cuits, means tortemporarily and simultaneously connecting a testing device to 'a'plural ty o't' telephone circuits, meansfor autoinatically and successively testing such circuits and lne ansi 'or preventing the advance of theautomatictesting of succeeding circuits responsive to the failiire of the tests' upon any one of said circuits.

' 8. system of'testing the electrical characteristics of jack circuits comprising. means Iior temporarily and simultaneously connecting a testing device to a plurality of such circuits, means for automatically and successively testingeuch circuits characterized by the provision of means fortesting the continuity of the tip, ring and sleeve conductors of said --cirou'its, and by the provision of 'm'eansfor applying another type of test; of the sleeve conductor to ascertainthe operating characteristicsof the corresponding cut-oft relay.

Inwitness whereof, We hereunto subscribe our names this 9th day of January A. D.,

19 26,*and on 14th January 1926.

WILLIAM L. LAWSON.

MYRONE. GANFIELD. 

